The present invention generally relates to a sheet feeding apparatus. More particularly, the invention relates to a sheet feeding apparatus for feeding a sheet from a sheet-accommodating cassette or a manually inserted sheet to a picture-forming (picture transfer) position.
Various apparatuses for forming a picture on a sheet material are known, including a picture recording apparatus in which a picture from a photosensitive material is transferred to a picture-receiving sheet. In this apparatus, for example, picture-receiving sheets are accommodated in a cassette and fed one by one to a picture transfer section. In order to feed a sheet accommodated in the cassette to the picture transfer section, for example, a semicircular roller is provided above the cassette. When the semicircular roller is rotated, the outer circumferential arcuate surface of the rollers abut the uppermost one of the sheets contained within the cassette to thereby draw out the uppermost sheet from the cassette by the frictional force acting between the semicircular roller and the sheet. The thus drawn-out sheet is then conveyed to the picture transfer section by conveying rollers.
Also, a manual-insertion sheet feeding apparatus is known in which a sheet material is manually fed by the operator. In such a manual-insertion sheet-feeding apparatus, the operator inserts a sheet into an insertion opening, and the sheet is guided along a guide member to conveying rollers.
A picture recording apparatus as described above has been proposed incorporating separately an automatic sheet-feeding apparatus and a manual-insertion sheet-feeding apparatus. In such a case, however, there is a problem in that the picture recording apparatus is large in size. Accordingly, a picture-receiving sheet feeding apparatus in which an automatic sheet-feeding function and a manual-insertion sheet-feeding function are integrally provided has been developed. A sheet feeding apparatus of this type is provided with, for example, a semicircular roller disposed above a cassette for accommodating sheets, a guide member for guiding a manually inserted sheet to a position below the semicircular roller, and a cover for closing the top operation of the cassette when a sheet is manually feed. When a sheet is automatically fed, the cover is moved to open the cassette so that the sheet in the cassette faces the semicircular roller so as to be fed by the semicircular roller, while when a sheet is to be fed manually, the cover is moved so as to close the cassette so that no sheet faces the semicircular roller, and a sheet is manually inserted at a position below the semicircular roller along the guide member so as to be fed by the semicircular roller.
In such an apparatus, however, there is a problem in that if the cassette is not closed by the cover when a sheet is manually fed, both the manually inserted sheet and a sheet from the cassette are simultaneously fed by the semicircular roller, causing jamming of sheets in the conveying system and making it impossible to carry out picture transfer effectively.